Rhizome long-scandent, fawn-coloured, 0.6-1 mm ø, deciduously scaly; scales light golden-brown, narrowly triangular, to 2 mm long, to 10-seriate at base, with a very short or virtually lacking uniseriate apex. Leaves 2-10 cm apart, issuing at about right angles; petioles quadrangular and sulcate almost to base, stramineous to reddish brown, often with paler angles, 4-15 cm long, somewhat shorter than the lamina. Lamina narrowly oblong, simply pinnate, 7-32 cm long, 3-6 cm wide, with 6-20 pinnules to a side, shortly acumi-nate; rachis stramineous, quadrangular, sometimes also quadrisulcate. Pinnules herbaceous, olivaceous when dry, spreading, alternate except the basal ones, their width apart to slightly over-lapping, sessile, subtrapezoidal to semi-ovate-ligulate, 1.5-3 cm long, 6-12 mm wide, 2 to almost 3 times as long as wide; upper margin straight or outward convex, a distinct outer margin sometimes developed, then forming an angle of 90° or less with the upper; upper (and outer) margin shallowly crenate, if fertile with c. 5 incisions and ± flat lobes, if sterile with more and closer incisions and rounded lobes, the deepest incisions to c. 1 mm, mostly not reaching the level of the receptacle. Few or very few upper pinnules suddenly reduced, one or two connected with the narrow, often caudate, to 4 cm long terminal segment. Veins immersed, evident, lax, anastomosing, forming an often incomplete series of areoles of varying length and l.5-2 mm maximum width between the margins. Sori single in the lobes, most often binerval, sometimes tri-or uninerval, 1-3 mm long, with straight or somewhat convex receptacle; indusium pale, delicate, subentire, free at the sides, 0.3-0.4 mm wide, not reaching the margin by 1.5-2 times its width, reflexed and +-concealed at maturity. Spores pale brown, trilete, smooth, c. 22 μ.
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